Sheldon: Checkmate.
Leonard: Oh, again?
Sheldon: Obviously, you're not suited for three dimensional chess. Perhaps three dimensional Candy Land would be more your speed.
Leonard: Just reset the board!
Sheldon: It must be humbling to suck on so many levels.

Leonard: What were you doing at Penny's?
Sheldon: Well, we had dinner, played some games, and then I spent the night. Oh, and you'll be happy to know that I now have a much better understanding of 'friends with benefits.'

Penny: Look, can we just forget about this extra stuff and can you just tell me what Leonard does?
Sheldon: Alright. Leonard is attempting to learn why subatomic particles move the way they do.
Penny: Really? That's it? Well, that doesn't sound so complicated.
Sheldon: It's not. That's why Leonard does it.

Sheldon: I am not crazy, my mother had me tested.

Sheldon: This is the temperature you agreed to in the roommate agreement.
Leonard: Aw, screw the roommate agreement!
Sheldon: No, you don't screw the roommate agreement. The roommate agreement screws you.

Sheldon: You did this, didn't you?
Wil Wheaton: Come on, Sheldon, do you really think I'd break up a couple just to win a bowling game?
Sheldon: No, I suppose not.
Wil Wheaton: Good. Keep thinking that.
Sheldon: Wheeeeatoooon!

Sheldon: Thanks, Dad. We're gonna give them hell.

Sheldon: Oh, what fresh hell is this?
Biosuit Nurse: Wait, you can't leave here, you've been exposed.
Sheldon: (Covering his face with his shirt) No, I haven't. It's all good.

Sheldon: You may not realize it, but I have difficulty navigating certain aspects of daily life. You know, understanding sarcasm, feigning interest in others, not talking about trains as much as I want. It's exhausting!

DMV Worker: Here's your learner's permit. Go away.
Sheldon: But I'm not done. I have many additional concerns about these questions.
DMV Worker: Don't make me climb over this counter!

Leonard: If you're worried, we can go over there and see if she's all right.
Sheldon: Okay. You know, I heard in the news a bobcat has been spotted in her neighborhood.
Leonard: I don't think Amy was eaten by a bobcat.
Sheldon: Who thinks Amy was eaten by a bobcat?
Leonard: You do?
Sheldon: Leonard, I was just mentioning an interesting local news item. Now, thanks to you, I'm worried Amy's been eaten by a bobcat.

Rajesh: Why so glum, chum?
Sheldon: Apparently you can't hack into a government supercomputer and then try to buy uranium without the Department of Homeland Security tattling to your mother.

Penny: I give up. He's impossible.
Sheldon: I can't be impossible; I exist. I think what you meant to say is, 'I give up; he's improbable'.

Leonard: Relax, it's just a dirty sock.
Sheldon: How on earth can you say "dirty sock" and "relax" in the same sentence?

Sheldon: Stop it both of you! All this fighting, I might as well be back with my parents!
*Imitating his Mom* Dammit, George! I told you if you didn't quit drinking I would leave you!
*Imitating his Dad* Well, I guess that makes you a liar, because I'm drunk as hell and you are still here!
*Imitating his Mom* Stop yelling, you're making Sheldon cry!
*Imitating his Dad* I'll tell you what is making Sheldon cry, that I let you name him SHELDON!